Secondary containment area panels

ABSTRACT

The present invention is directed to an apparatus and method for constructing a secondary containment for above ground storage units. A site is selected for the storage unit and preparing the foundation bed. A containment wall comprised of a plurality of joined panels is constructed. The panels have a wall joined to a foot, with the wall being substantially planar and comprised of rigid material and the foot being joined to the bottom section of the wall. The foot is substantially planar and comprised of rigid material, extending angularly and inwardly from the wall. The plurality of the panels are joined in a closed geometric configuration to form a containment wall, presenting an interior region. A liner is secured in the interior region and a protective coating is applied to the interior region of the containment wall.

PRIORITY

The present invention claims priority to provisional application 61/809,995, which has a filing date of Apr. 9, 2013 and is hereby incorporated by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to spill and leak containment, more specifically to an apparatus and method for containing leaks from above ground storage tanks.

2. Description of the Related Art

During the production of oil or gas from an underground well, it is common for liquid containing contaminants to be produced along with the oil or gas. One such liquid, “produced water,” is typically separated from the oil or gas at the well site and temporarily stored in above ground storage tanks. The produced water can have high quantities of minerals, salts, oil, gas, sand, and other substances dissolved, mixed, or suspended in it. A vehicle with a large storage tank attached to it periodically travels to the well site and transfers the produced water from the above ground storage tank to the storage tank of the vehicle for transport, processing, and/or disposal.

Produced water with a high concentration of impurities can be corrosive to the walls and ancillary piping of an above ground storage tank causing leaks of the contaminated liquid into the environment. Environmental law and regulations require that facilities that store large quantities of contaminated liquid must have a plan in place to contain a spill. With regards to above ground storage tanks, it is typically required that a secondary containment area be in place to collect any accidental discharge of produced water from an above ground storage tank in use. The secondary containment area usually needs to have the capacity and strength to hold more than the volume of the above ground storage tank, or for an array of above ground storage tanks, more than the largest above ground storage tank in the array. A need exists for an efficient, higher strength, more quickly deployable, and inexpensive method of building the secondary containment area for an above ground storage tank.

SUMMARY

The present invention is directed to an apparatus and method for constructing a secondary containment for above ground storage units. A site is selected for the storage unit and preparing the foundation bed. A containment wall comprised of a plurality of joined panels is constructed. The panels have a wall joined to a foot, with the wall being substantially planar and comprised of rigid material and the foot being joined to the bottom section of the wall. The foot is substantially planar and comprised of rigid material, extending angularly and inwardly from the wall. The plurality of the panels are joined in a closed geometric configuration to form a containment wall, presenting an interior region. A liner is secured in the interior region and a protective coating is applied to the interior region of the containment wall.

These and other features, aspects, and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side perspective view of an embodiment of a panel according to the current invention;

FIG. 2 illustrates a side view of an embodiment of two joined panels;

FIG. 3 illustrates a side perspective view of a partially complete containment area comprising the panels of FIG. 2;

FIG. 4 illustrates a side perspective view of a completed containment area comprising the panels of FIG. 2;

FIG. 5 illustrates a side perspective view of a completed containment area comprising the panels of FIG. 2 having an above ground storage tank in its interior;

FIG. 6 illustrates a side perspective view of a completed containment area comprising the panels of FIG. 2 having an array of above ground storage tanks in its interior; and

FIG. 7 illustrates an embodiment of a method for creating a containment area for an above ground storage tank employing the panels of FIG. 2.

DETAILED DESCRIPTION

Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.

The present invention includes at least one panel 10 for building a containment wall 30 and a method for constructing a secondary containment area for one or more above ground storage tanks 08 using the same.

Referring to FIG. 7, an exemplary process for constructing a secondary containment area is shown. Initially, the site is selected and the foundation bed 28 is prepared 100. The containment wall 30 is constructed 110. A liner 36 is secured to the containment wall 130. A protective coating is applied to the interior region of the containment wall 140. After deployment of above ground storage tank(s) 08, this results in a containment area, such as that illustrated in FIGS. 5 and 6. Each of these steps will be considered in more detail below.

As disclosed above, the site is selected and the foundation bed 28 is prepared 100. Referring to FIG. 3, a foundation bed 28 is depicted. The exemplary foundation bed 28 is composed of gravel or dirt. In an exemplary process, the foundation bed 28 is leveled.

The containment wall 30 is constructed from a plurality of panels 110. Referring now to FIG. 1, an exemplary panel 10 is shown. The panel 10 includes a cap 14, a wall 18, and a foot 22. The wall 18 is a rigid, substantially planar length of material capable of bearing load. Its exemplary composition is a metal such as steel. In exemplary configuration, the wall 14 thickness ranges from 10-14 gauge. Its exemplary height range is about three foot tall. Its exemplary (longitudinal) width ranges from about four feet to about twelve feet.

A foot 22 is rigidly joined to the wall 18 and extends angularly and inwardly from the wall 18. The foot 22 is also a rigid, substantially planar length of material capable of bearing load. Its exemplary composition is a metal such as steel. In exemplary configuration, it is substantially orthogonal to the wall 14. In an alternate configuration, it is from about 90° to 110°. In another alternate configuration, it is from about 75° to 90°. Its exemplary (latitudinal) length is about nine inches. In one configuration, its length is about ¼ of the height of the wall 18. In an alternate configuration, its length is greater than about ⅙ of the height of the wall. Its exemplary (longitudinal) width equals that of the wall 18 and ranges from about four feet to about twelve feet.

Optionally, a cap 14 is rigidly joined to the wall 18 and extends angularly and outwardly from the wall 18 in an opposing direction to the foot 14. The cap 14 is also a rigid, substantially planar length of material. Its exemplary composition is a metal such as steel. In exemplary configuration, it is substantially orthogonal to the wall 18. Its exemplary length is about three inches. Its exemplary (longitudinal) width equals that of the wall 18 and ranges from about four feet to about twelve feet. Optionally, its distal end includes a downwardly depending segment.

The exemplary manner of making the panel 10 is bending a single sheet of steel, whereby the wall 18, foot 22, and optional cap 14 form a rigidly unitary piece.

In continuing to build the containment wall 110, two panels 10 are joined, preferably sealably joined along the walls 18 and feet 22 of the two panels 10. Referring now to FIG. 2, two adjacent panels 10 are joined at opposing ends. In one method, the two adjacent panels 10 are welded. In another method, a brace 26 is placed on the cap 14 side of the panels 10 and spanning the ends of the panels 10. The depicted brace 26 is welded to the two panels 10 and the feet 22 are welded together. In alternate configurations, the panels 10 are mechanically joined using fasteners such as screws. In one method, the panel 10 is anchored to the foundation bed 28. Common anchoring approaches included subterranean anchoring or cement anchoring. In one configuration, an extension of the brace 26 extends downwardly past the bottom of the wall 18, whereby the extension is used to anchor.

In continuing to build the containment wall 110, plural panels 10 are joined. Referring to FIG. 3, plural panels 10 are joined to form a containment wall 30 having an interior region 33 and exterior region 31. Plural panels 10 are joined and anchored with the feet 22 facing the interior region 33 of the containment wall 30 and the caps 14 facing the exterior region 31 of the containment wall 30. The depicted plural panels 10 are joined in a rectangular arrangement, although it should be appreciated that the plural panels 10 can be joined in other geometric configurations, preferably closed geometries.

A liner 36 is secured to the interior region 130. The liner 36 can be composed of a geotextile, blown fabric, felt, or an equivalent fabric with some degree of absorption so that the coating 32 can adhere to the liner 36. The liner 36 can be secured to the panel 10 by any means known to those skilled in the art, but it is preferably secured by bolts directly into the foot 22 and wall 18, or by a series of straps secured to the lining 36 by screws. Alternatively, the liner 36 is secured to the panels 10 using an adhesive, such as polyurea.

A coating 32 is applied to the liner 36 to form a solid, impermeable layer 120. A suitable coating 32 is applied as a substrate to at least a portion of the liner 36, preferably the complete liner 36. Suitable coatings 32 include those resistant to contaminants as disclosed above. A suitable coating 32 is applied as a substrate to at least a portion of the liner 36. A suitable coating is one which is resistant to reaction with, dissolution in or with, permeation by, or other interaction with the contaminants or the liquid of an above ground storage tank 08 which may escape and could affect the integrity of the coating 32. One suitable substance is polyurea. Polyurea is an elastomer that is derived from the reaction product of an isocyanate component and a synthetic resin blend component. Polyurea suitable for the present invention is available from Sherwin Williams under the name EnviroLastic AR200HD or Versaflex FSS 50DM. The polyurea coating 32 is preferably applied using a spray device. One or more coats is applied to form a solid, impermeable layer. A representative, now completed secondary containment area is depicted in FIG. 4.

In operation, at least one above ground storage tank 08 is situated in the interior region 33 of the containment wall 30. FIG. 5 depicts a single above ground storage tank 08 while FIG. 6 depicts an array of above ground storage tanks 08. In the event that liquid escapes from above ground storage tank 08, it is contained within the secondary storage area where a truck with a storage tank can transport the spilled liquid.

Insofar as the description above and the accompanying drawing disclose any additional subject matter that is not within the scope of the single claim below, the inventions are not dedicated to the public and the right to file one or more applications to claim such additional inventions is reserved. 

1. An apparatus for forming a containment wall, said apparatus comprising: a wall joined to a foot; said wall being substantially planar and comprised of rigid material; said foot joined to the bottom section of said wall, said foot being substantially planar and comprised of rigid material, said foot extending angularly and inwardly from said wall.
 2. The device of claim 1, wherein said foot is about 90° relative to said wall.
 3. The device of claim 1, wherein said foot is from about 90° to about 110° relative to said wall.
 4. The device of claim 1, wherein said foot is from about 75° to about 90° relative to said wall.
 5. The device of claim 1, wherein the length of said foot is about ¼ of the height of said wall.
 6. The device of claim 1, wherein the length of said foot is greater than ⅙ of the height of said wall.
 7. The device of claim 1, wherein said wall and foot comprise a single sheet of folded metal.
 8. The device of claim 1, further comprising a cap, said cap joined to the upper section of said wall and extending outwardly from said wall.
 9. The device of claim 8, wherein said wall, foot, and cap comprise a single sheet of folded metal.
 10. The device of claim 1, further comprising a brace.
 11. A method for constructing a secondary containment for above ground storage units, comprising the steps of: selecting a site for said storage unit and preparing the foundation bed; providing a panel comprised of a wall joined to a foot, said wall being substantially planar and comprised of rigid material, said foot joined to the bottom section of said wall, being substantially planar and comprised of rigid material, said foot extending angularly and inwardly from said wall; sealably joining a plurality of said panels in a closed geometric configuration to form a containment wall, presenting an interior region; securing a liner in the interior region; and applying a protective coating to said interior region of the containment wall.
 12. The method of claim 11, wherein said panel comprises a single piece of folded metal.
 13. The method of claim 11, further providing a brace and welding said brace to opposing ends of adjacent panels.
 14. The method of claim 11, further providing mechanical fasteners and mechanically fastening opposing ends of adjacent panels.
 15. The method of claim 11, further providing a brace and anchoring said brace into said foundation bed.
 16. The method of claim 15, wherein the method comprises subterranean anchoring.
 17. The method of claim 15, wherein the method comprises cement anchoring.
 18. The method of claim 11, wherein said foot is angled about 90° relative to said wall.
 19. The method of claim 11, wherein said foot is angled from about 90° to about 110° relative to said wall.
 20. The method of claim 11, wherein said foot is angled from about 75° to about 90° relative to said wall. 